Sudden cardiac death (SCD) accounts for -50% of all CHD deaths and, forthe majority of victims, SCD is the first manifestation of heart disease. There is an accumulating body of evidence that fatty acids, particularly n-3 fatty acids, hold great promise as predictors of and preventive interventions against SGD, although studies have been inconsistent. These conflicting results may be due to differences in population characteristics (with and without CHD; men v. women) or methods of fatty acid assessment (dietary intake v. biomarker levels). Thus, more research is needed to understand the differences in risk among these various subgroups and to evaluate different methods of fatty acid measurements. Additionally, genetic and environmental influences on fatty acid metabolism are not well understood. During the K99 award, Dr Chiuve successfully implemerited a comprehensive training plan, which inclijded mentored training through the analysis of dietary fatty acids and genetic influences of fatty acid rnetabolism and risk of SCD, other significant scientific research training, attendance at seminars and researeh conferences and nonscientific career development. She has gained the knowledge and skills necessary for the transition into an independenfinyestigator in the field of Nutritional Epidemiology of Cardiac Arrhytmic Disorders. During the ROO phase of the award. Dr. Chiuve w.iil assay fatty acids in fed blood cells and.examine their association with risk of SCD. She will also exaniine the influence of genetic variation in RBC fatty acids. She will investigate these aims within 6 large, NIH-funded prospective cohort studies that include both men and women and individuals with and without established CHD. Strengths of this proposalinclude the use of dietary and RBC fatty acid measures as means to predict individuals at high risk of SCD and the identification of subgroups that may benefit from a low-cost treatment such as modifying dietary fatty acid intake. These aims correspond to one goal in the NHLBl's strategic plan to develop means to predict and prevent sudden cardiac death.